1. Field of Invention
The invention relates to buckles and more particularly to an adjustable buckle for tightening or loosening two straps joined thereat, each strap being extended from either end piece of a mask (e.g., one used for swimming or diving, one worn by an athlete, or a safety mask).
2. Description of Related Art
A conventional mask (e.g., one used for swimming or diving, one worn by an athlete, or a safety mask) has one or two head straps. For a mask having a single strap, a strap tensioner is mounted at either end piece of the mask. For a mask having two straps each extended from either end piece of the mask, a buckle is generally disposed at a rear central portion of the brain when a person wears the mask. As comparing the buckle with the strap tensioners, the buckle is more advantageous because it is simple in construction and can simplify the mask component.
However, the construction of the well known buckle is complicated and its use is not unreliable. Thus, the need for improvement still exists.